Orangutan

Orangutan youngsters depend on their mothers during their early years. Newborns will cling to their mother’s front continuously for nearly a year, and will continue to ride around on her until about 2½ years of age. They are weaned at about 3½ years old.

Shy creatures of the forest, orangutans are Asia’s largest primates, and its only great apes. They are also the largest fully tree-dwelling animals in the world. With a striking human resemblance, these red apes have long been subjects of legends and myths, fascinating many early explorers and naturalists.

Long ago found throughout East and Southeast Asia, orangutans are now restricted to the islands of Sumatra and Borneo, where they live in shrinking pockets of freshwater swamp forest and lowland rainforest. Sumatran and Bornean orangutans represent distinct species, the former known as Pongo abelii and the latter as Pongo pygmaeus. The IUCN Red List categorizes Sumatran orangutans as Critically Endangered, and Bornean orangutans as Endangered.

Orangutans are the most arboreal of all the great apes, spending long portions of their day foraging in trees, searching for fruits. They have been called the gardeners of the forest, and play a vital role in seed dispersal. With their highly mobile hip joints and opposable toes, they can swing through the canopy and hang upside down using just their feet to support their whole weight. This agility, together with their intelligence and largely solitary lifestyle, make them well adapted to survive in their jungle homes. Environmental pressures, however, mean their future is uncertain.

Fast Facts

Scientific Name

Pongo pygmaeus & Pongo abelii

Orangutans have lived on our planet for up to 2 million years, originating during the Pleistocene Era.

Humans share 96.4% of our genes with orangutans; however, we are more closely related to chimps and gorillas, which also share more of their DNA with us than with orangutans.

Tool use by orangutans rivals that of chimps; one population of orangutans in Sumatra uses 54 different tools for extracting insects, and 20 for preparing fruits.

Early travelers coined the English name “orangutan” from the words “orang hutan” in the Malay and Indonesian languages, meaning forest person. Local people use other names for the animal, however, such as mawas, kahui, and kisau.

Adult male orangutans, which are twice as big as females, can also be extremely loud. Their haunting roars can be heard up to a kilometer (.6 miles) away.

Wild figs top the list of this ape’s favorite fruits.

Challenges

As more of their habitat is converted for logging, oil palm plantations, and other human uses, orangutan numbers continue to decline. Adding to their vulnerability are the facts that orangutans produce only one offspring every five years or so, live at low densities, and require large home territories—a problem as human activities increasingly fragment their jungle habitats. Even within their two remaining island habitats, their range is very limited. In Sumatra, orangutans only occur in the far northern province of Aceh and small parts of its adjoining provinces.

Though illegal, hunters continue to target these apes for food, sport, the trophy and pet trade, and as crop pests. (In fact, some orangutan field biologists believe that the arboreal habits and solitary nature of these apes developed as a defense mechanism to avoid the ages-old persecution by humans.) Public awareness and law enforcement have helped reduce hunting in many areas, but constant vigilance is needed to control it. Even within current park boundaries, some degree of encroachment and poaching remains a threat to dwindling orangutan populations.

WCS Responds

Ensuring a future for these precious red apes requires improved law enforcement, expanded protected areas, effective protection of those reserves, and ensuring that logging is done in ways that can allow wildlife to survive within forest reserves. WCS is working to implement these conservation measures across the orangutan’s remaining range.

WCS has been involved in Sarawak, a Malaysian state on the island of Borneo, since the 1960s, when noted conservationist Dr. George Schaller conducted pioneering surveys of orangutans. More recently, WCS has helped create a management plan for one of the key national parks where they occur and provided key training to the law enforcement staff who protect the park. Further, WCS, together with Sarawak Forestry Corporation, is surveying orangutans in the area, assessing the major threats they face, and developing strategies to conserve them. WCS also partners with the Sarawak Forestry Corporation to help raise awareness of these threats among local communities and schools through conservation education programs.

On the Indonesian side of Borneo and in the Leuser Ecosystem of Sumatra, WCS's Wildlife Crimes Unitshas assisted the Government of Indonesia to make noteworthy arrests of wildlife traders attempting to sell baby orangutans into the pet trade. WCS works in partnership with the Indonesian Department of Forestry and local law enforcement agencies to protect these and other endangered species.